Patent GB-292974-A (GB)
Title: Improvements in method and apparatus for torpedo firing operations
IPC: F41G9/00
Filed: 1928-06-05
Abstract: 292,974. Florisson, C. L. June 28, 1927, [Convention date]. Locating subaqueous sounds.-The position and speed of a target. are determined and recorded on a chart by means of submarine " echo " observations, and the chart is used in conjunction with vectors representing other data for determining the correct direction in which a torpedo should be launched against the target and the point of impact. Sound vibrations are emitted and their " echo '' from the target are observed by known apparatus in which the emitter or receiver or both are directive, to enable the direction of the target, to be determined. This direction is transmitted by any known mechanism to a repeater 7, Fig. 1, connected by gearing 22 to the spindle 25 of an arm 11 rotatable over a chart table 1, so that this arm is automatically kept in the direction of the target. The range or distance of the target is proportional to the time elapsing between the emission of the sound and the reception of the echo. The sound is emitted automatically at regular intervals when a switch 38 is closed under the control of a device 10 running at a constant speed. At the same moment, a clutch 9 connects the spindle 2 of the device 10 to a screw 8 along the arm 11. This screw drives a nut 13 from the centre of the table, which coincides with the axis of the spindle 2, towards the end of the arm 11. When the echo is received an electromagnet 15 automatically depresses a device, 14 carried along by the nut 13. and this device marks a point on the chart. As the speed of the nut 13 is constant, the radial distance from the centre of the chart of the point marked by the device 14 is proportional to the time which elapses from the emission of the sound to the reception of the echo, and is therefore proportional to the range of the target; and this being measured along the arm 11, which is maintained in the direction of the target, it follows that the mark on the chart represents to the scale of the chart the position of the target relatively to the observing post. When the nut 13 reaches the end of the arm 11 it deflects a stop 6, and this throws the clutch 9 out, and allows a spring device 16, which has been wound up by the operative rotation of the screw 8, to rotate the screw in the opposite direction and return the nut 13 with the marker 14 to the centre of the table in readiness for the next operation of the switch 38, when the above functions are repeated and a fresh mark made on the chart. It results from these operations recurring at fixed time intervals, that the distance between the marks is a measure of the speed of the target. Over the table is mounted a vector triangulating mechanism comprising an arm 3, Figs. 1 and 2, with a rider 17 set from the centre 2 to a distance corresponding to the speed of the observing post but in the opposite direction, a second arm 18 with a rider 19 set relatively to the rider 17 to represent the speed and direction of the torpedo, and a third arm 20 with a rider 21 set relatively to the rider 19 to represent the speed of the target but in the opposite direction, this speed and direction being obtained from the last two marks on the chart. The line joining the centre 2 to the rider 21 thus gives the correct line of sight, and the torpedo should be launched when the target represented by the marks on the chart crosses this line of sight. Further the crossing of the line 17, 18 by the line of the marks represents the actual point of impact and enables the operator to ascertain the accuracy of the hit by comparison with the noise of the explosion picked up by t.he receiving apparatus, it being then more easy to identify the, noise of the explosion from other noises that might also be picked up. During the period which elapsesbetween the return of the marker 14 to the centre and its next operation, an observer may send out sounds under hand control and by noting their echoes keep up his location of the target. Just before the switch 38 is due to start the automatic operation, another switch 39 gives a signal, warning the operator that the automatic operation is about to begin. A switch is provided to enable the operator to control clutch 9 so that he may put it in action only when he has ascertained the location of the target.